Liquid crystal display device and manufacturing method thereof

ABSTRACT

A method of manufacturing a liquid crystal display device including a TFT substrate with display and peripheral regions. The display region has pixels each having a pixel electrode and a TFT. A counter substrate opposes the TFT substrate and has a color filter formed at a position corresponding to a position at which the pixel electrode is formed above the TFT substrate. The method includes coating, outside of the display region of the TFT substrate, a second alignment film in the shape of a frame, and coating, in the display region, a first alignment film that dries more slowly than the second alignment film. The first and second alignment films are in contact, and the second alignment film is thicker than the first alignment film.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/986,528, filed on Dec. 31, 2015, which, in turn, is a continuation ofU.S. patent application Ser. No. 13/966,823 (now, U.S. Pat. No.9,257,458), filed on Aug. 14, 2013, which, in turn, is a continuationapplication of U.S. patent application Ser. No. 13/004,056 (now, U.S.Pat. No. 8,514,356), filed on Jan. 11, 2011, the entire contents ofwhich are incorporated herein by reference.

CLAIM OF PRIORITY

The present application claims priority from Japanese Patent ApplicationJP 2010-007068 filed on Jan. 15, 2010, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device. The inventionparticularly relates to a liquid crystal display device that can beformed as a so-called narrow frame type in which a display region ismade larger relative to a predetermined outer shape.

2. Description of the Related Art

A liquid crystal display device has a TFT substrate and a countersubstrate opposed to the TFT substrate. The TFT substrate includespixels arranged in a matrix, each pixel having a pixel electrode and athin film transistor (TFT). The counter substrate includes a colorfilter formed at a position corresponding to a position at which thepixel electrode is located above the TFT substrate. Liquid crystals areput between the TFT substrate and the counter substrate. Images areformed by controlling the light transmittance of liquid crystalmolecules for every pixel.

Since liquid crystal display devices are flat in shape and light inweight, their uses have been extended in various fields. Small-sizedliquid crystal display devices have been used generally, for example, inmobile phones or DSC (Digital Still Camera), etc. For the small-sizedliquid crystal display devices, there is a strong demand to enlarge adisplay region while keeping the outer shape of the device small. Then,the width between the end of the display region and the end of theliquid crystal display device becomes narrow and so it is necessary toprovide a so-called narrow frame.

A seal member for bonding the TFT substrate and the counter substrate isapplied to a narrow frame region. On the other hand, an alignment filmfor initial alignment of liquid crystals is formed in the display regionof the liquid crystal display device. Since it is necessary that thealignment film cover the display region reliably, the area to coat thealignment film has to be larger by a predetermined width than that ofthe display region. On the other hand, when the alignment film ispresent between the seal member and the TFT substrate or between theseal member and the counter substrate, the reliability of bonding by theseal member will deteriorate. Accordingly, the alignment film should notoverlap with the seal member. Even if the alignment film and the sealmember overlap each other, it is necessary that the overlapping regionextend not over the entire surface thereof but partially.

The alignment film has been formed by flexographic printing. Since, inthe flexographic printing, the viscosity of the alignment film beforebaking can be made higher, the outer shape of the alignment film can becontrolled accurately. On the other hand, the market recently requiresvarious types of sizes for the liquid crystal display devices. When theflexographic printing is used, the printing plates have to be preparedfor every size, resulting in problems in the manufacturing cost of theprinting plates and the number of steps in the line of exchange theprinting plates.

Manufacturing the alignment film by ink jet printing may cope withmanufacture of liquid crystal display devices of various types andvarious sizes. However, when the alignment film is to be formed by inkjet printing, it is necessary to lower the viscosity of the alignmentfilm. However, if the viscosity of the alignment film is low, thealignment film flows out to the outside after coating of the alignmentfilm, thus making it difficult to accurately control the outer shape ofthe alignment film.

JP-A-2008-145461 describes that unevenness is formed at the periphery ofan under layer film forming the alignment film to use the unevenness asa stopper when the alignment film flows to the outside after coating.

SUMMARY OF THE INVENTION

In the technique described in JP-A-2008-145461, unevenness is formed atthe periphery of an insulating film carrying an alignment film thereon,that is, in the vicinity of a seal portion. Then, ITO (Indium Tin Oxide)formed simultaneously with a pixel electrode is disposed to a portion ofthe insulating film where the unevenness is formed, thereby preventingthe alignment film from flowing out to the outside.

However, this method is disadvantageous in that when the alignment filmis filled fully in the concave portion formed at the periphery of theinsulating film, the alignment film further flows out to the outside.The ITO film is formed in the concave portion at the periphery of theinsulating film; however since the thickness of the ITO film is, forexample, 70 nm or less, it is difficult for the ITO film to function asstopper having a sufficient height.

Further, although the configuration in JP-A-08-145461 can be applied onthe side of the TFT substrate, disadvantageously it is not applicable onthe side of the counter substrate since the film configuration on theside of the counter electrode is different from that on the side of theTFT substrate.

The present invention intends to provide a narrow frame type liquidcrystal display device with high reliability when an alignment film isformed by ink jet printing, by preventing the alignment film fromflowing out to the outside thereby accurately controlling the outershape of the alignment film.

The present invention overcomes the problems described above andprovides the following specific embodiments.

(1) According to a first aspect of the present invention, there isprovided a liquid crystal display device including a TFT substratehaving a display region and a peripheral region, the display regionhaving pixels arranged in a matrix, each pixel having a pixel electrodeand a TFT; and a counter substrate opposed to the TFT substrate, thecounter substrate having a color filter formed at a positioncorresponding to a position at which the pixel electrode is formed abovethe TFT substrate, the TFT substrate being bonded to the countersubstrate by way of a seal member in a seal portion located at theperiphery,

wherein a first alignment film is formed in the display region of theTFT substrate, and a second alignment film is formed at the peripheralregion outside of the display region and at the outside of the firstalignment film, the second alignment film being not formed in thedisplay region, and

wherein the first alignment film is in contact with the second alignmentfilm.

(2) A liquid crystal display device as described in (1) above, whereinthe thickness of the second alignment film is larger than the thicknessof the first alignment film.

(3) A liquid crystal display device as described in (1) above, whereinthe second alignment film is in contact with the seal member.

(4) According to a second aspect of the present invention, there isprovided a liquid crystal display device including a TFT substratehaving a display region and a peripheral region, the display regionhaving pixels arranged in a matrix, each pixel having a pixel electrodeand a TFT; and a counter substrate opposed to the TFT substrate, thecounter substrate having a color filter formed at a positioncorresponding to a position at which the pixel electrode is formed abovethe TFT substrate, the counter substrate having a display region and aperipheral region, the TFT substrate being bonded to the countersubstrate by way of a seal member in a seal portion located at theperiphery,

wherein a first alignment film is formed in the display region of theTFT substrate, and a second alignment film is formed at the peripheralregion outside of the display region and at the outside of the firstalignment film, the second alignment film being not formed in thedisplay region, the first alignment film being in contact with thesecond alignment film; and

wherein a first alignment film is formed in the display region of thecounter substrate, a second alignment film is formed at the peripheralregion outside of the display region and at the outside of the firstalignment film, the second alignment film is not formed in the displayregion, and the first alignment film is in contact with the secondalignment film.

(5) A liquid crystal display device as described in (4) above, whereinthe thickness of the second alignment film is larger than the thicknessof the first alignment film.

(6) According to a third aspect of the present invention, there isprovided a method of manufacturing a liquid crystal display deviceincluding a TFT substrate having a display region and a peripheralregion, the display region having pixels arranged in a matrix, eachpixel having a pixel electrode and a TFT; and a counter substrateopposed to the TFT substrate, the counter substrate having a colorfilter formed at a position corresponding to a position at which thepixel electrode is formed above the TFT substrate, the TFT substratebeing bonded to the counter substrate by way of a seal member in a sealportion located at the periphery, the method comprising the steps of:

coating at the periphery outside of the display region of the TFTsubstrate, by ink jet printing, a second alignment film in the shape ofa frame, and

then coating in the display region, by ink jet printing, a firstalignment film drying more slowly than the second alignment film suchthat first alignment film is in contact with the second alignment film.

(7) According to a fourth aspect of the present invention, there isprovided method of manufacturing a liquid crystal display deviceincluding a TFT substrate having a display region and a peripheralregion, the display region having pixels arranged in a matrix, eachpixel having a pixel electrode and a TFT; and a counter substrateopposed to the TFT substrate, the counter substrate having a colorfilter formed at a position corresponding to a position at which thepixel electrode is formed above the TFT substrate, the counter substratehaving a display region and a peripheral region, the TFT substrate beingbonded to the counter substrate by way of a seal member in a sealportion located at the periphery, the method comprising the steps of:

coating at the periphery outside of the display region of the TFTsubstrate, by ink jet printing, a second alignment film in the shape ofa frame, and

then coating in the display region, by ink jet printing, a firstalignment film drying more slowly than the second alignment film suchthat first alignment film is in contact with the second alignment film,

coating at the periphery outside of the display region of the countersubstrate, by ink jet printing, a second alignment film in the shape ofa frame,

then coating in the display region of the counter substrate, by ink jetprinting, a first alignment film drying more slowly than the secondalignment film such that the first alignment film is in contact with thesecond alignment film, and

then bonding the TFT substrate and the counter substrate by way of aseal member.

According to the present invention, the outer shape of the alignmentfilm can be controlled accurately even when the alignment film is formedby ink jet printing. Accordingly, a liquid crystal display device of anarrow frame can be manufactured reliably and at a low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a liquid crystal display device to which thepresent invention is applied;

FIG. 2 is a cross-sectional view along line A-A in FIG. 1;

FIG. 3 is a plan view of a TFT substrate according to the invention;

FIG. 4 is a cross-sectional view of an end portion of a TFT substrateaccording to the invention;

FIG. 5 shows an example of a method of forming an alignment film by inkjet printing; and

FIG. 6 shows another example of a liquid crystal display deviceaccording to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is to be described specifically by way of thefollowing embodiments.

[First Embodiment]

FIG. 1 is a plan view of a small-sized liquid crystal display deviceused for a mobile phone or the like which is an example of a product towhich the invention is applied. In FIG. 1, a counter substrate 200 isdisposed above a TFT substrate 100. A liquid crystal layer notillustrated is put between the TFT substrate 100 and the countersubstrate 200. The TFT substrate 100 and the counter substrate 200 arebonded by a seal member 20 formed at a frame portion. In FIG. 1, sinceliquid crystals are sealed by one drop filling method, a sealing hole isnot formed.

The TFT substrate 100 is formed larger than the counter substrate 200. Aterminal portion 150 for supplying power, video signals, scanningsignals, etc. to a liquid crystal display panel is formed at a portionby which the TFT substrate 100 is made larger than the counter substrate200.

Further, an IC driver 50 for driving a scanning signal lines 30, videosignal lines 40, etc. is disposed to the terminal portion 150. The ICdriver 50 is divided into three regions in which a video signal drivingcircuit 52 is disposed at the central portion and scanning signaldriving circuits 51 are disposed on both sides thereof.

In a display region 10 in FIG. 1, scanning signal lines 30 extend in thelateral direction and are arranged in the vertical direction. Further,video signal lines 40 extend in the vertical direction and are arrangedin the lateral direction. Regions each surrounded by the scanning signallines and the video signal lines define a pixel. The scanning signallines 30 are connected from opposite sides of the display region 10 byway of scanning signal line leads 31 to the scanning signal drivingcircuits 51 of the IC driver 50. Video signal line leads 41 that connectthe video signal line 40 and the IC driver 50 are gathered on the lowerside of a screen and connected with the video signal driving circuit 52disposed in the central portion of the IC driver 50.

In FIG. 1, the display region 10 is completely covered by an alignmentfilm not illustrated. The alignment film is formed by ink jet printing.However, as described later, the alignment film does not overlap withthe seal member 20, or even if they overlap each other, the alignmentfilm only partially overlaps with the seal member 20 but does notoverlap with the entire surface of the seal member 20. Then, while thealignment film is formed by ink jet printing, a narrow frame can beattained as the distance from the end of the display region 10 to theend of the liquid crystal display device is about 1.5 mm.

FIG. 2 is a cross-sectional view along line A-A in FIG. 1. FIG. 2 is anexample of a so-called TN type liquid crystal display device in whichpixel electrodes 107 are formed above the TFT substrate 100 and acounter electrode 204 is formed above the counter substrate 200. Theinvention is applicable not only to the TN type but also to liquidcrystal display devices such as an IPS (In Plane Switching) type, inwhich pixel electrodes and counter electrodes are formed on the side ofthe TFT substrate 100. Further, while FIG. 2 shows a structure based ona so-called top gate type TFT in which poly-Si is often used for asemiconductor layer, the invention is applicable in the same manner alsoto the case of a so-called bottom gate type TFT in which a-Si is oftenused for the semiconductor layer.

In FIG. 2, above the TFT substrate 100 are formed a first underlayerfilm 101, a second underlayer film 102, a gate insulating film 103, aninterlayer insulating film 104, an inorganic passivation film 105, andan organic passivation film 106 that also functions as a planarizingfilm, in this order. The first underlayer film 101 and the secondunderlayer film 102 are used for preventing impurities deposited from aglass substrate from contaminating a not illustrated semiconductor layerin the display region 10. The gate insulating film 103 is used forinsulating a not illustrated gate electrode and the semiconductor layer,and the interlayer insulating film 104 is used for insulating the gateelectrode or a scanning line 30 and a source/drain electrode or a videosignal line 40. The inorganic passivation film 105 protects a notillustrated TFT in the display region 10 and the organic passivationfilm 106 has a function as a passivation film, as well as a function ofplanarizing the unevenness on the surface caused by TFTs or wirings.

Pixel electrodes 107 are formed above the planar organic passivationfilm 106 in the display region 10. A display region alignment film 108is formed to cover the pixel electrodes 107 in the display region 10. Itis necessary that the display region alignment film 108 cover the entiredisplay region 10 reliably.

At the outside of the display region 10, a peripheral alignment film 109is formed above the organic passivation film 106. The display regionalignment film 108 is formed also at the outside of the display region10 in order to reliably cover the display region 10. The peripheralalignment film 109 has a role of accurately defining, as a stopper, thecoating region of the alignment film, thereby preventing the displayregion alignment film 108 from spreading to the periphery. As describedabove, the invention has a feature in using two types of alignmentfilms, that is, the display region alignment film 108 and the peripheralalignment film 109. In the seal portion, the seal member 20 is formeddirectly on the organic passivation film 106.

In FIG. 2, a color filter 201 and a black matrix 202 are formed in thedisplay region 10 of the counter electrode 200, and the black matrix 202is formed at the outside of the display region 10. An overcoat film 203is formed to cover the color filter 201 and the black matrix 202. Theovercoat film 203 has a role of preventing the effect of the colorfilter 201 on the liquid crystal layer 250 and planarizing the surfaceof the color filter 201 and the black matrix 202.

The counter electrode 204 made of ITO is formed in a solid coating abovethe overcoat film 203. Then, in the display region 10, the displayregion alignment film 108 is formed to cover the counter electrode 204.Further, the peripheral alignment film 109 is formed at the outside ofthe display region 10. The peripheral alignment film 109 has a role ofaccurately defining, as a stopper, the coating region of the alignmentfilm, thereby preventing the display region alignment film 108 fromspreading to the periphery.

A liquid crystal layer 250 is put between the TFT substrate 100 and thecounter electrode 204. The liquid crystal layer 250 is sealed by theseal member 20 formed at the periphery of the TFT substrate 100 and thecounter electrode 204. The seal member 20 is in direct contact with theorganic passivation film 106 in the TFT substrate 100 and is in directcontact with the overcoat film 203 in the counter substrate 200 and,usually, the alignment film is not present therebetween.

In FIG. 2, while the peripheral alignment film 109 is formed to have anarrow width, the thickness thereof is larger than the thickness of thedisplay region alignment film 108. The peripheral alignment film 109prevents the display region alignment film 108 from spreading to theperiphery, thereby preventing the alignment film from being formed belowthe seal member 20. Accordingly, the seal portion of the invention hashigh bonding reliability.

FIG. 3 is a plan view only for the TFT substrate 100 in FIG. 1. In FIG.3, the seal member 20 is formed at the periphery of the TFT substrate100. The seal member 20 is often formed above the counter substrate 200in the manufacturing process. FIG. 3 shows a region in which the sealmember 20 presents. The peripheral alignment film 109 is formed incontact with the inside of the seal member 20.

The peripheral alignment film 109 is shown such that it is in contactwith the inside of the seal member 20. However, there may be actually acase where a slight gap is formed between the peripheral alignment film109 and the seal member 20 or a case where the peripheral alignment film109 slightly overlaps with the seal member 20 depending on the variationin the manufacture. Even in the case where the peripheral alignment film109 overlaps with the seal member 20, since the amount of overlap isslight, this scarcely affects on the reliability of the seal portion. InFIG. 3, the display region alignment film 108 covers the entire area ofthe display region 10 and is in contact with the inside of theperipheral alignment film 109.

FIG. 4 is a cross-sectional view along line B-B in FIG. 3. In FIG. 4,layers at or lower than the organic passivation film 106 below the pixelelectrodes 107 in the TFT substrate 100 are not illustrated. FIG. 4shows an example for respective dimensions at the periphery. In FIG. 4,the distance w0 from the end of the display region 10 to the end of theTFT substrate 100 is 1.5 mm, to form a narrow frame.

In FIG. 4, the size w1 from the end of the TFT substrate 100 to the endof the seal member 20 is 0.2 mm. The size w1 is a necessary size wheneach of the liquid crystal cells is separated from a mother substrate500 by scribing. This is because each of the liquid crystal cells cannotbe separated when the scribing line is present inside the seal member20.

In FIG. 4, the width w2 of the seal member 20 is about 0.7 mm. The sizeis necessary for keeping the reliability of bonding. A peripheralalignment film 109 is formed in contact with the seal member 20. Thewidth w3 of the peripheral alignment film 109 is 0.2 mm. While a smallersize is more preferred for the width of the peripheral alignment film109, it is defined as about 0.2 mm since the film is coated by ink jetprinting. The width w3 can be changed according to the drying speed ofthe ink for the peripheral alignment film 109.

In FIG. 4, the distance w4 from the end of the display region 10 to theend of the peripheral alignment film 109 is 0.4 mm. In other words, thecoating range for the display region alignment film 108 can be madelarger than the display region 10 by about 0.4 mm on one side. When thedisplay region alignment film 108 is coated, since the peripheralalignment film 109 has already been dried and solidified, the peripheralalignment film 109 can function as a stopper to the display regionalignment film 108.

The invention has a feature in forming two types of the alignment films.That is, the quick drying peripheral alignment film 109 is formed at theoutside of the display region 10 and the display region alignment film108 is formed in the display region 10 and between the display region 10and the peripheral alignment film 109. To form the alignment films byink jet printing, it is necessary to eliminate the unevenness of thefilms by a leveling effect after coating the alignment films. However,when the alignment film dries quickly, the leveling effect is notprovided sufficiently.

However, if the drying speed of the alignment film is made slower forobtaining the leveling effect, this results in a problem that thealignment film spreads to the periphery, thereby making the control forthe outer shape of the alignment film difficult. That is, in the ink jetsystem, uniformity of the alignment film and accurate control of theouter shape of the alignment film are in a trade-off relation. Accordingto the invention, the quick drying peripheral alignment film 109 isformed in the frame shape at the periphery of the display region 10 andthe outer shape of the display region alignment film 108 is controlledaccurately by the peripheral alignment film 109.

A process for forming the alignment films by ink jet printing in thepresent invention is as described below. That is, the display regionalignment film 108 is first coated by ink jet printing. Since the inkfor the peripheral alignment film 109 dries quickly, it is solidified ata predetermined width and a thickness before the spreading of thealignment film. The width w3 of the peripheral alignment film 109 can becontrolled to about 0.2 mm and the thickness t2 thereof can be made to100 nm or more.

Successively, the display region alignment film 108 is coated by ink jetprinting. It is necessary that a leveling effect be caused sufficientlyin the display region alignment film 108 to such an extent that theunevenness of the alignment film can be eliminated. For this purpose, itis necessary that the drying speed of the alignment film be slow. Whenthe drying speed of the alignment film is slow, the alignment film tendsto spread to the periphery. Therefore, control for the outer shape ofthe alignment film by the ink jet printing has been difficult so far.

In the invention, since the peripheral alignment film 109 is formed,then dried and solidified at the instance the display region alignmentfilm 108 is coated, the outer shape of the display region alignment film108 is defined by the peripheral alignment film 109, and can be entirelycontrolled accurately. In order to obtain the effect described above, itis necessary that the peripheral alignment film 109 be formed to have athickness t2 larger than the thickness t1 of the display regionalignment film 108.

The thickness t1 of the display region alignment film 108 is about 100nm. In contrast, even when the thickness t2 of the peripheral alignmentfilm 109 is made larger than 100 nm, it is easy to keep the width w3 ofthe peripheral alignment film 109 to about 0.2 mm since the film driesquickly. Easy controllability for the width of the peripheral alignmentfilm 109 means that the outer shape of the entire alignment film can becontrolled. If the alignment film dries quickly, no sufficient levelingeffect is obtained so that unevenness is formed on the film. However,since the peripheral alignment film 109 is formed at the outside of thedisplay region 10, unevenness of the peripheral alignment film 109 doesnot give an undesired effect on the image quality.

Since the peripheral alignment film 109 and the display region alignmentfilm 108 are coated separately, the boundary between the peripheralalignment film 109 and the display region alignment film 108 can beobserved by a microscope as shown in FIG. 4. Further, since thethickness of the peripheral alignment film 109 is larger than thethickness of the display region alignment film 108, presence of theperipheral alignment film 109 and that of the display region alignmentfilm 108 can also be distinguished in this regard.

While it has been described above that the peripheral alignment film 109is coated and then the display region alignment film 108 is coated, thetime interval from the coating of the peripheral alignment film 109 tothe coating of the display region alignment film 108 can be changedvariously in a range from an extremely short time to a relatively longtime. The time interval from the coating of the peripheral alignmentfilm 109 to the coating of the display region alignment film 108 isdetermined according to the extent of the drying speed of the peripheralalignment film 109.

In FIGS. 3 and 4, the configuration on the side of the TFT substrate 100has been explained. However, the configuration of the alignment filmdescribed with reference to FIGS. 3 and 4 is applicable also to the sideof the counter substrate 200. That is, while the film structure formedbelow the alignment film is different between the TFT substrate 100 andthe counter substrate 200, a quite identical method of forming thealignment film can be applied to the TFT substrate 100 and the countersubstrate 200.

FIG. 5 is a schematic view showing an example of a method of coating analignment film in the invention. In FIG. 5, a plurality of TFTsubstrates 100 are formed on a mother substrate 500. That is, aftercompleting the manufacturing process in the state of the mothersubstrate 500, it is bonded with a mother substrate formed with aplurality of counter substrates. Then, each of the liquid crystal cellsis separated by scribing. Coating of the alignment film is alsoperformed in the state of the mother substrate 500.

In FIG. 5, the peripheral alignment film 109 is coated by a first head301, and a plurality of nozzles corresponding to the coating region areprovided in the first head 301. The display region alignment film 108 iscoated by a second head 302 and a plurality of nozzles corresponding tothe coating region are provided in the second head 302. The positionsfor the nozzles are different between the first head 301 and the secondhead 302. FIG. 5 shows a state in which ink jet printing 350 for thealignment film is discharged from the nozzles of the first head and thesecond head.

In FIG. 5, the first head 301 first moves along an arrow to coat theperipheral alignment film 109. Since the peripheral alignment film 109dries quickly, it is dried and solidified instantly after the coating.Successively, the second head 302 moves following after the first head301 as shown by an arrow to coat the display region alignment film 108.To obtain the leveling effect sufficiently, the drying speed of thedisplay region alignment film 108 is slow and the film tends to spreadto the periphery after the coating. However, as shown in FIG. 4, sincethe peripheral alignment film 109 coated by the first head 301 hasalready been dried and solidified, the peripheral alignment film 109serves as a stopper, so that the display region alignment film 108spreads no more.

In FIG. 5, the time interval from the movement of the first head 301 tothe movement of the second head 302 can be determined according to thedrying speed of the peripheral alignment film 109. When the peripheralalignment film 109 dries quickly, the second head 302 can be movedimmediately after the movement of the first head 301. In this case, evenwhen two types of alignment films are coated, the tact time scarcelyincreases. It has been described for the mother substrate 500 on theside of the TFT substrate 100 in FIG. 5. However, it is possible to coatthe peripheral alignment film 109 and the display region alignment film108 also to a mother substrate 500 on the side of the counter substrate200 in the same manner.

FIG. 6 is an example modified from that of FIG. 2. In FIG. 2, the widthw3 of the peripheral alignment film 109 is made larger than that in FIG.2 and the film 109 partially overlaps with the seal member 20. Theallowance for the coating of the peripheral alignment film 109 can beincreased by so much as the width w3 of the peripheral alignment film109 is increased. Other structures in FIG. 6 are identical with those inFIG. 2.

In FIG. 6, the peripheral alignment film 109 partially overlaps with theseal member. However, since the amount of the overlap is small, thisdoes not give any significant effect on the adhesion between the sealmember 20 and the organic passivation film 106 in the TFT substrate 100or on the adhesion between the seal member 20 and the overcoat film 203in the counter substrate 200. As described above, even when theallowance for the coating of the peripheral alignment film 109 is madelarger, the reliability of the seal portion at the periphery can bemaintained.

In the explanations described above, it has been described that thedisplay region alignment film 108 and the peripheral alignment film 109are formed in the same manner above the TFT substrate 100 and thecounter substrate 200. However, specific effects according to theinvention can be obtained also when two types of alignment films arecoated only to one of the TFT substrate 100 and the counter substrate200 because of some or other situations.

What is claimed is:
 1. A liquid crystal display device comprising: a TFTsubstrate having a display region and a peripheral region, the displayregion having pixels, each of the pixels having a pixel electrode and aTFT; a counter substrate opposing to the TFT substrate, the TFTsubstrate being bonded to the counter substrate by a seal member locatedin the peripheral region; and a liquid crystal layer sandwiched betweenthe TFT substrate and the counter substrate; wherein a first alignmentfilm and a second alignment film are formed on a liquid crystal side ofthe TFT substrate, a drying rate of a material of the second alignmentfilm is faster than a drying rate of a material of the first alignmentfilm.
 2. The liquid crystal display device according to claim 1, whereinthe first alignment film is formed in the display region and the secondalignment film is formed in the peripheral region.
 3. The liquid crystaldisplay device according to claim 2, wherein the second alignment filmis in contact with the seal member, a black matrix is formed on thecounter substrate, the black matrix overlaps with the second alignmentfilm, in a plan view.
 4. The liquid crystal display device according toclaim 1, wherein a thickness of the second alignment film is thickerthan a thickness of the first alignment film.
 5. A liquid crystaldisplay device comprising: a TFT substrate having a first display regionand a first peripheral region, the display region having pixels, each ofthe pixels having a pixel electrode and a TFT; and a counter substrateopposing to the TFT substrate, the counter substrate having a seconddisplay region and a second peripheral region, the TFT substrate beingbonded to the counter substrate by a seal member in the first peripheralregion, wherein a first alignment film and a second alignment film areformed on a liquid crystal side of the TFT substrate, a third alignmentfilm and a fourth alignment film are formed on a liquid crystal side ofthe counter substrate, drying rates of a material of the secondalignment film and the fourth alignment film are faster than dryingrates of a material of the first alignment film and a material of thethird alignment film.
 6. The liquid crystal display device according toclaim 5, wherein the first alignment film is formed in the first displayregion, the third alignment film is formed in the second display region,the second alignment film is formed in the first peripheral region, andthe fourth alignment film is formed in the second peripheral region. 7.The liquid crystal display device according to claim 6, wherein thesecond alignment film and the fourth alignment film are in contact withthe seal member, a black matrix is formed on the counter substrate, theblack matrix overlaps with the fourth alignment film.
 8. The liquidcrystal display device according to claim 5, wherein a thickness of thesecond alignment film and a thickness of the fourth alignment film arethicker than a thickness of the first alignment film and a thickness ofthe third alignment film.